Network resilience
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www.criticalcomms.com March 2020
high bandwidth for data, increased reliability and low latency
features that will come as the 5G standard matures with
Release 16-17 and 18. In addition, with slicing capabilities,
5G will also mean that mobile operators can offer a
designated resilient service with guaranteed quality of service
for public safety use over their public networks.
“But slicing services will also require mobile operators to
expand the coverage of their 5G network currently limited
to major cities. These kind of capabilities brought by the
new 5G standards will come during 2021-2023, and devices
that support these features a few years after.”
Boesch from Damm observes: “Do public safety users
need to have separate cores? Many vendors do offer
IP applications running on smartphones that can get
tunnelled and encrypted/authenticated through any kind
of IP backbone to connect to the secured centralised or
decentralised core.”
Raquel Frisa, product manager – Systems, LTE and
Command & Control at Teltronic, takes a different view
on separate cores in a 4G network. “The use of a separate
network core is essential to guarantee the reliability in
broadband networks. But this is not the only requirement
when the public agency needs to deliver mission-critical
(MC) services. In fact, our recommendation also involves
the use of dedicated RAN infrastructure in some critical
areas, the use of dedicated spectrum whenever it is possible
and the agreement of SLAs in case of hybrid models of
network operation (eg, MVNO).”
Frisa continues: “Failover mechanisms between PMR,
LTE and Wi-Fi are essential in order to guarantee the
Failover mechanisms between PMR,
LTE and Wi-Fi are essential in
order to guarantee service availability
availability of the service for the users, and this feature has
been already included in the scope of 3GPP standardisation
under the paradigm of ‘Interworking’, understood as the
continuity of services implemented across broadband and
narrowband networks.
“Until this specification is completed and can be extended
to other broadband technologies like Wi-Fi, some end-users
are demanding proprietary solutions in order to cover their
service availability requirements.”
The game of 9s
Whether the goal is 99.9 or 99.999 per cent availability,
resilience will not happen without thought and planning.
The approach taken by FirstNet (see box) and others in
understanding the views and needs of end-users and their
organisations will lay down the targets for overall resilience
and areas of special need.
Careful analysis will identify the particular areas for
developing resilience. Increasingly, networks are partnerships
between multiple suppliers, and so establishing closely
working teams with clear KPIs and service-level agreements
becomes vital. Fall-back strategies which may involve using
reserve equipment and personnel also need to be considered,
as well as training and regular exercises.
Resilience
measures for
mission critical
4G LTE networks
will depend to
some extent on
whether they are
private dedicated
networks with
their own
spectrum or
commercial
operators
providing services
to both mission
critical users and
consumers
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